def factorial(n): if n == 0 or n == 1: return 1 else: return n * factorial(n-1) num = 5 print(factorial(num))解释一下

这段代码定义了一个名为 `factorial` 的函数，用于计算给定正整数 `n` 的阶乘。

解释一下函数的实现过程：

1. 函数首先进行条件判断，如果 `n` 的值为 0 或者 1，即 `n` 是特殊情况下的边界值，那么直接返回结果 1。这是因为 0 和 1 的阶乘都是 1。
2. 如果 `n` 不是边界值，那么执行 `else` 分支的代码，计算 `n` 乘以 `factorial(n-1)` 的结果。这里使用了递归的方式，将问题转化为更小规模的子问题。
3. 在递归调用中，将 `n` 的值减去 1，传递给下一次递归调用。这样每次递归都会处理一个较小的数字，逐步向边界值逼近。
4. 当递归到达边界值时，开始回溯并计算阶乘结果。每次回溯时，将得到的结果乘以当前的 `n` 值。
5. 最终，递归调用返回的结果就是整个阶乘的结果。

例如，如果调用 `factorial(5)`，函数会递归地计算 5 * 4 * 3 * 2 * 1，最终返回结果为 120。

相关问题

def factorial(n): if n == 0: return 1 else: return n * factorial(n-1) n = 10 print(factorial(n))

The above code defines a function named "factorial" that takes an integer "n" as input and recursively calculates and returns the factorial of "n".

The factorial of a non-negative integer "n" is defined as the product of all positive integers less than or equal to "n". For example, the factorial of 5 is 5 x 4 x 3 x 2 x 1 = 120.

The code then sets the value of "n" to 10 and calls the "factorial" function with "n" as input. The result (3628800, the factorial of 10) is printed to the console.

def factorial(n): if n == 0: return 1 else: return n * factorial(n-1)

This is a recursive function to calculate the factorial of a given number.

The factorial of a number is the product of all integers from 1 to that number. For example, the factorial of 5 is 5 x 4 x 3 x 2 x 1 = 120.

The function takes in a parameter 'n', which is the number whose factorial is to be calculated. If the number is 0, the function returns 1 (since the factorial of 0 is 1). Otherwise, it recursively calls itself with n-1 as the parameter and multiplies the result with n. This continues until n reaches 0, at which point the function returns the final result.